It is never difficult to distinguish between a Scotsman with a grievance and a ray of sunshine, said the English comic writer PG Wodehouse. Baillie Gifford, the great Edinburgh-based fund manager, has more reason than most to feel aggrieved after its high-flying fund, Edinburgh Worldwide Investment Trust (stock market ticker: EWI) fell victim to a hostile takeover bid by American arbitrageurs.

That drama was well-covered elsewhere but much less attention focused on an issue of wider importance; how EWI outperformed its unit trust rival – a similar pooled fund from the same management company, focussed on the same investment sector, with the same individual fund manager. Nor is there anything unusual about how this investment trust delivered substantially more to shareholders over the last decade and one-year periods than its unit trust rival, sometimes called a ‘sister fund’.